The present invention is directed to apparatuses for handling data, such as digital information, and especially to apparatuses for accessing a plurality of devices by a system with a plurality of devices coupled with the system via a single communication port. The apparatus is especially useful when the various devices have different operating speeds. The present invention is advantageously employed in a video recording system that exchanges digital video data with a two storage devices using a single communication port.
Many data handling apparatuses involve systems communicating at high speeds with storage devices via communication ports. Some such apparatuses have more than one storage device with which a system communicates. One example of such an apparatus is a real-time video apparatus that records a video stream to either a DVD (Digital Video Disc) or to an HDD (Hard Disc Drive) and plays back video information from those media. Controlling communications (i.e., recording and playback) with two or more media is difficult, especially when the media operate at different speeds. When different speeds are involved among various media, the slowest medium can be a bottleneck in the operation of the apparatus, effectively limiting the overall speed of operation of the apparatus.
Some prior art apparatuses seek to avoid such a bottleneck effect by providing two communication ports for carrying out required communications with two devices. One port is coupled with the slower device; the other port is coupled with the faster device. This arrangement has a drawback in that it tends to require embodiment in a physically larger product to accommodate the second communication port because two interface modules are required for the two ports. The added module also adds expense to the two port product as compared with a product having a single port.
There is a need for an apparatus and method that can carry out communications via a single communication port with a plurality of devices having different communicating speeds.